<template>
    <div class="sidebar">
        <el-menu class="sidebar-el-menu" :default-active="onRoutes" :collapse="collapse" unique-opened router>
            <template v-for="item in items">
                <template v-if="item.subs">
                    <el-submenu :index="item.index" :key="item.index">
                        <template slot="title">
                            <i :class="item.icon"></i>
                            <span slot="title">{{ item.title }}</span>
                        </template>
                        <template v-for="subItem in item.subs">
                            <el-submenu v-if="subItem.subs" :index="subItem.index" :key="subItem.index">
                                <template slot="title">{{ subItem.title }}</template>
                                <el-menu-item v-for="(threeItem, i) in subItem.subs" :key="i" :index="threeItem.index"
                                    >{{ threeItem.title }}
                                </el-menu-item>
                            </el-submenu>
                            <el-menu-item v-else :index="subItem.index" :key="subItem.index">{{ subItem.title }} </el-menu-item>
                        </template>
                    </el-submenu>
                </template>
                <template v-else>
                    <el-menu-item :index="item.index" :key="item.index">
                        <i :class="item.icon"></i>
                        <span slot="title">{{ item.title }}</span>
                    </el-menu-item>
                </template>
            </template>
        </el-menu>
    </div>
</template>

<script>
import bus from '../common/bus';

export default {
    data() {
        return {
            collapse: false,
            items: [
                {
                    icon: 'el-icon-lx-home',
                    index: 'dashboard',
                    title: '系统管理',
                    subs: [
                        {
                            index: 'emp',
                            title: '员工管理'
                        },
                        {
                            index: 'dept',
                            title: '部门管理'
                        },
                        {
                            index: 'post',
                            title: '岗位管理'
                        },
                        {
                            index: 'errand',
                            title: '出差管理'
                        },
                        {
                            index: 'salary',
                            title: '薪资管理'
                        },
                        {
                            index: 'role',
                            title: '角色管理'
                        },
                        {
                            index: 'resource',
                            title: '资源管理'
                        },
                        {
                            index: 'notice',
                            title: '通知管理'
                        }
                    ]
                },
                {
                    icon: 'el-icon-lx-warn',
                    index: '/donate',
                    title: '系统监控',
                    subs: [
                        {
                            index: 'operLog',
                            title: '日志管理'
                        },
                        {
                            index: 'sql',
                            title: '数据监控'
                        }
                    ]
                }
            ]
        };
    },
    computed: {
        onRoutes() {
            return this.$route.path.replace('/', '');
        }
    },
    created() {
        // 通过 Event Bus 进行组件间通信，来折叠侧边栏
        bus.$on('collapse', (msg) => {
            this.collapse = msg;
            bus.$emit('collapse-content', msg);
        });
    }
};
</script>

<style scoped>
.sidebar {
    display: block;
    position: absolute;
    left: 0;
    top: 70px;
    bottom: 0;
    overflow-y: scroll;
}

.sidebar::-webkit-scrollbar {
    width: 0;
}

.sidebar-el-menu:not(.el-menu--collapse) {
    width: 250px;
}

.sidebar > ul {
    height: 100%;
}
</style>
